Communication system



May 7, 1935. w. s. LEMMON COMMUNICATION SYSTEM Filed Feb. 15, 1934 w n k L m w l. A R mm Q vi w n Wm a n m A TTORNEYS Patented May 1, 1935 2,000,765

UNITED STATES PATENT OFFICE;

Walter S. Lemmon, New York, N. Y., assignor, by S mesne assignments, to International Business Machines Corporation, New York, N. Y., a corporation of New York v Application February 15, 1934, Serial No. 711,313

9 Claims. (01. 178-53) v This invention relates to communication sysductor 8 with the hub portion of a sending colt'ems employing synchronous, in-phase operalector 9. The battery is effective to produce tion of a transmitter and a receiver, and applies an impulse through the transmitting means I particularly to a system wherein the intelligence each time that the collector arm 9 wipes across 4 is conveyed by electrical impulses identified by the contact 2. The collector arm 9 rotatesat I their timing with reference to an arbitrary uniform .speed and hence the operating im-. time scale. pulses are sent out at uniform time intervals.

For such a system it is desirable that the Between successive'operating impulses the colsender include a rotary signal impulse collector lector arm 9 wipes across all of the signal con-- 7 l. which is operated at uniform speed and that tacts 3 in predetermined order completing a cir- 10 the receiver include a rotary signal distributor 'cuit through the transmitter 'I as it touches each which is operated at the same speed. contact. The contacts 3 are adapted to be se- In accordance with the present invention, lectively charged by means not shown, and any correspondence between the speeds of the sendsuch contact that is charged will cause an im- I ll ing collector and the receiving distributor is pulse to be sent out as the collector arm 9 secured by causing an operating impulse to be wipes across it. Such an impulse will obviously transmitted by the sender at a predetermined be timed with reference to the operating im- I point in each cycle of the sending collector, and pulse, in accordance with the position of the by providing in the receiver a frequency responparticular character contact which is charged.

sive operating motor for the distributor which These character contacts are so disposed around 20 is adapted to be operated at the same speed as the circumference of the collector that they are the sending collector by energy supplied at the pa ed o the op ra ing-impulse contact 2 frequency of the received operating impulses. by a time distance greater than the length of It is a feature of the invention that the opthe operating-impulse.

2 crating impulses and the signal impulses which e send may b used in l e te esral hy or are received together after phase correspondence C ri r cur ent Systems or for radio. A'radio has been established are separated and disa tenna I0 is indicated. tinguished by the receiver so that the signal In t e eiver, an antenna H is connected to impulses are not permitted to affect the distribuan amplifier l2 andthis a lifier connected t r operating means. through a conductor H to a battery H. The 30 It is a further feature of the invention that t y H is in turn Connected through a provision is made in the receiver of frequency ductor IS with the hub portion of a rotary multiplying means and of distributor operating distributor arm IS. The distributor arm l6 means responsive to the multiplied frequency of carries two brushes which are electrically condistributor at the same speed as the sending t d t w p a ross contacts 26 which are collector. mounted on a stationary disc 21 and which cor- Other objects and advantages will hereinp d i their pos tions with the signal 00nafter appear. tacts 3 of the sender. The other brush forms In the drawing forming part of this specificapart of a device I! which closes a circuit between 40 tion, conductor 15 and either a ring segment 22 or Figure l. is a diagrammatic view illustrating ac 3, 24 a d 5. the sending and receiving apparatus; and The ring segment-22 and the contacts 2 3, 24 Figure 2 is a fragmentary diagrammatic view d 25 are the sameas the sorrespondlhgly illustrating another form of apparatus embodynumbered Da disclosed in y P n pphing features of the inventi n. I cation, Serial No. 684,362, filed August 19, 1933, The sender comprises a commutator ring 1 for Synchronizing y In el{l a 0 which includes an operating-impulse contact di cl r i ma e of the i of lltlhzlng W 2 and a multiplicity of signal contacts a of ar r f rr d to h r in-as t p ti i p ls which only a few are illustrated. The operat for adjusting the rec v di r u into pha e ing-impulse contact is connected through a conjcorrespondence with the sending distributor. In ductor l to a battery 5, thence through a com the pres t app y a serve sa e ductor t to a suitable transmitting or broadpurpose, but they are additionally utilized (amcasting. means indicated by the rectangle I. plified) to actually drive the distributor arm l6. The transmitting means 1 is connected by con- The ring segment 22 and the contacts 23, 24

35 the operating impulses to operate the receiving nected to one another. One of these brushes is 35 contact 25. Such impulses never come through.

on the ring segment 22 after phase correspondence has once been secured. Signal impulses are not transmitted until the phase correspondence has been secured at which time the ring segment 22 is open circuited to render it inoperative.

In normal operation, the operating impulses are transmitted through a conductor 59, an electromagnet 60, and conductors 63 and-58 to a conductor 10. The conductor 10 is connected to one terminal of an amplifier II. The other terminal of the amplifier II is connected through" a conductor I2 to a terminal of the amplifier l2- to complete the output circuit of the amplifier The electromagnet 60 normally holds up an armature 33 against the force of a spring. The ring segment 22 is provided with a contact 32 with which the armature 33 is adapted to engage when released by the electromagnet 60. When the apparatus is first set into operation, and before any letter impulses have been transmitted, the operating impulses may be transmitted through the ring segment22, contact 32 and armature 33 to a conductor 34. Such current passes thence through an advancing relay A to conductor 10. As soon as in-phase operation is produced, however, the operating impulses are transmitted through contact 24 and electromagnet 6.0 so that armature 33 is held away from contact 32. This condition is maintained so. long as in-phase operation continues, the result being that no impulses transmitted while the arm I6 is in register with the ring segment 22- can get through to conductor 10. When an impulse is transmitted with the arm engaging contact 23, the current travels through advancing relay A, causing in-phase operation to be immediately restored. This single cycle interruption of the normal circuit through 24 is not of sufllcient'duration to permit armature 33 to move into engagement with contact 32. Similarly, when-the operating impulse is transmitted from arm 16. through contact 25, the current passes through a conductor 55, retarding relay R and conductor 58 to conductor 10, causing inphase operation to be restored while maintaining the ring segment 22 inoperative.

The mechanism just described is effective both to prevent signal impulses from reaching the amplifier 1|, and to transmit power operating impulses to said amplifier. Line current is applied to said amplifier from line terminals 13 and 14, and the output circuit 15 of the amplifier is connected througha transformer T with a circuit 16 which includes the field winding 11 quency by driving the shaft 80 at the same rotary speed as that at which the collector arm 9 of the sender is driven.

In the embodimentof Figure 2 the sending apparatus may be as the same as that of Figure l and hence has not been illustrated. The receiving apparatus is also the same as that of Figure 1 with the exception of certain features which will be referred to below. The receiver comprises an antenna Ila and an amplifier I241. The current is transmitted through a conductor 13a and a device I'Ia, 21a to a conductor Illa which is connected to one terminal of an amplifier and frequency multiplier Ila. Any one of the several types of frequency multipliers well known in the art may be employed, such, for example, as the magnetic doubler type or the vacuum tube type. A conductor 12a connects the opposite terminal of the amplifier and frequency multiplier Ha with the amplifier l2a, completing the output circuit of the amplifier I211. The frequency multiplier and amplifier I la, both of which may be of any suitable type well known in the art, are supplied with current from line terminals 13a. and 14a, and the output circuit 15a is inductively connected through transformer Ta with a circuit 1611 which includes the field winding 11a of a phonic motor 180.. The motor includes a rotor 190 which is connected to drive the shaft 80a upon which the distributor arm (not shown) is mounted. The rotor 190 may be provided as shown in Figure 2 with a larger number of segments than the rotor I9 of Figure l. The increase in number may correspond to the frequency multiplications effected by the frequency multiplier.

In such case the effect of frequency multiplication is to produce a finer degree of responsiveness to the operating impulses and a smoother application of power. If preferred, however, the frequency multiplication may be utilized to alter in an advantageous manner the gearing employed, or possibly to obviate the need for gearing. This feature of stepping up the frequency is an important feature where more than one impulse per revolution of the sending collector is wanted, since it is desirable to avoid the complications which would be introduced by attempting to transmit from the sender a plurality of operating impulsesin a singlerevolution of the sending collector.

Thave described what I believe to be the best embodiments of my invention. I do not wish, however, to be confined to the embodiments shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim:

1. In a system for conveying intelligence by electrical impulses, in combination, a sender comprising a collector operating at uniform speed and a receiver comprising a distributor adapted to operate at substantially the same speed, said system including means in the sender for transmitting a distributor-operating impulse at a predetermined point in each cycle,

and signal impulses at---other times, means in the receiver responsive to the reception of the operating impulses to rotate the distributor at the same speed as the sending collector, and to adjust it' into phase correspondence, and means responsive to phase correspondence for discriminating between the operating and signal impulses.

2. In a. system for conveying intelligence by electrical impulses, in combination, a sender adapted to operate at substantially the same speed, said system including means in the sender for transmitting a distributor-operating impulse at a predetermined point in each cycle, means in-the receiver responsive to reception of the operating impulses to rotate the distributor at the same speed as the sending collector, means in the receiver for initially transmitting the operating impulses through to the operating means regardless of the phase relation of the sender and the receiver, means for adjusting the receiver into phase correspondence with the sender, and means for thereafter excluding from the operating means impulses transmitted in the interval between successive operating impulses.

3. In a system for conveying intelligence by electrical impulses, in combination, a sender comprising a collector operating at uniform speed and a receiver comprising a distributor adapted to operate at the same speed, said systemincluding means in the sender for transmitting a distributor-operating impulse at a predeterminedinstant in, each cycle and signal impulses at other times, means in the receiver responsive to reception of the operating impulses to rotate the distributor at the same speed as the sending collector and in phase correspondence therewith, and means in the receiver responsive to phase correspondence for excluding from the operating means impulses received between successive operating imp 4. In a system for conveying intelligence by electrical impulses, in combination, a sender, and a receiver comprising a rotary distributor adapted for operation at a predetermined uniform speed, said systemincluding means in the sender for transmitting distributor-operating impulses at uniform time intervals, and signal impulses between successive operating impulses, means in the receiver responsive to said operating impulses to operate the distributor, and means in the receiver responsive to phase correspondence said sender including means of the sender and receiver for preventing s nal impulses from affecting the distributor operating means.

5'. In a system for conveying intelligence by electrical impulses, in combination, a sender and a receiver, saidreceiver including a rotary distributor and means for rotating the same, and for transmitting distributor-operating impulses at uniform time intervals, and means in the receiver for utilizing the operating impulses both to eifect the driving a of the receiver distributor and to produce and maintain phase correspondence of the receiver with the sender.

- comprising means for transmitting operating impulses atuniform time intervals and signal impulses at other times, and a receiver comprising a rotary distributor, means for operating the distributor, a source of electrical energy, means controlled by the operating impulses for causing energy from said source to be supplied periodi-' cally to the distributor-operating means, and. means responsive to phase correspondence of between the signal and operating impulses.

7. Ina system for conveying intelligence by the sender and distributor for discriminating electrical impulses. in combination,.a sender comprising a collector operating at uniform speed and a receiver comprising a distributor adapted to operate at substantially the same speed, means in the sender for transmitting a distributor-operating impulse at a single predetermined point in each cycle, and for sending signal impulses between successive operating impulses, means in the receiver for receiving the operating impulses and multiplying the frequency of the same, means responsive to such multiplied frequency to rotate the distributor at the same speed as the sending collector, and means responsive to phase correspondence of the sender and distributor for discriminating between the signal and operating impulses.

8. In a system for conveying intelligence by electrical impulses, in combination, a sender comprising a collector operating at uniform speed, and a receiver comprising a distributor adapted to operate at the same speed, said system including means in the sender for transmitting distributor operating impulses at uniform time intervals and for sending signal impulses between successive operating impulses,

means in the receiver for receiving the operating quency to rotate the receiving distributor at the same speed as the sending collector, and means responsive to phase correspondence of the sender and distributor for discriminating between the signal and operating 9. In a system for conveying intelligence by electrical impulses, in combination, a sender comprising a collector normally operating at substantially uniform speed, and a receiver comprising a distributor adapted to operate in synchronism with the collector, said system including means in the sender for transmitting distributor operating impulses at the same period in each cycle of the collector and signal impulses at other times, means in the receiver responsive to the reception of the operating impulses to 1y with the collector even when the speed of the collector varies, and means responsive'to phase correspondence of the sender and distributor for discriminating between the signal and operating impulses.

\ WALTER S. LEMMON. 

